In a new study, Brazilian geologist dates the origin of the Amazon river

A study published this week, conduced by a team of scientists lead by Brazilian geologist Jorge Figueiredo, revealed that the Amazon river, world's biggest river in volume of water has born 11.8 million years ago. The research shows various interesting details about the "teenage" and the "adult phase" of the river as well, such as the fact the Eastern Amazon region, close to the Atlantic ocean, had a smaller river during the Middle Miocene, while the Western portion, where Peru, Colombia and Brazilian states of Amazonas and Acre lie, was a big, wet area similar to a swamp.

But things begin changing 11.8 million years back, says the geologists, partly due to the rising ice sheets in Antartida, which lowered the sea level, and partly because of the Andean range reaching dizzy heights. Both processes ended about 11.3 million years ago and connected the western swamp lakes to the eastern creek: the Amazon river was born. In its kindergarten years, which ended 6.8 million years ago, lots of lakes were surrounding the river, which had a curvy flow and whose sediments begin lying in the continent.

The teenage years of the Amazon were marked by bigger volumes of sediments, brought by the further growing of the Andes. It began obliterating the lakes, which paved the way to the adult stage. The great news from the study lie on dating the various stages of this evolution; besides, it is another move against an other theory over the creation of the river: other researchers pointed that the Amazon river has born 5 million years ago, flowing from the Atlantic to what would be the Andes in the future.

We at Portal do Geólogo would like to join Brazilian senator Arthur Virgílio, which praised the study last Thursday at the Senate, and congrat mr. Figueiredo and his staff for the research, a giant step for the studies of Brazilian geology.